Observations from weather stations can be used in various ways to improve weather forecasts. With one method commonly called post-processing, observations are used for any or all of the following steps: a) statistically correct individual numerical weather prediction (NWP) forecast models, b) guide consensus combinations of those models for generating an improved forecast, and c) ensure the forecast matches the observation for the current time at the observation location.
In general, the forecasts are computed in a centralized forecasting location, distant from where the observations are made. The observations are transmitted electronically to the forecasting location, generally in a form such that those observations are quantitatively identifiable by someone at the forecasting location. In some cases, for privacy purposes it is undesirable to transmit the observations in identifiable form to the forecasting location. Normally, this would mean that no forecast can be provided for which the observations are used in its computation, since any encryption would normally require decryption at the forecasting location. Accordingly, there is a need for coded weather data.